html,
body {
	margin: 0;
	padding: 0;
}

body {
	text-align: center;
}

.warpper {
	width: 300px;
	height: 200px;
	border: 1px solid #008080;
	position: absolute;
	left: 50%;
	top: 50%;
	margin-left: -150px;
	margin-top: -150px;
	padding-top: 100px;
}

#grade {
	height: 30px;
}

#btn {
	height: 35px;
}